1. Field of the Invention
The present invention relates generally to an improved method and apparatus for mounting elements such as gear pins and standoffs to a plate. More particularly, the invention relates to a method and apparatus that permits a plurality of such elements to be installed in a single operation at desired locations on a plate.
2. Description of Related Art
A number of assembled mechanical and electro-mechanical devices, such as actuators, meters, measurement devices and the like, are constructed of two or more plate-like elements arranged generally parallel to one another and held in spaced relation by standoffs. Movable elements such as gears, levers and the like are typically mounted on pins between the plates and interlinked to cooperatively carry out the function of the device. While the standoffs themselves may serve to support certain of the functional elements, this task is more often reserved for the pins, the standoffs serving only to maintain spacing between the plates and to unify the assembly. Moreover, because such functional elements typically subject the mounting pins to considerable axial and radial loading during operation, the pins must be solidly supported on one of the plates to maximize the accuracy and useful life of the device. Similarly, the standoffs must resist loading transmitted to the plates and ensure the structural integrity of the assembly.
Devices of the type described above are generally assembled by first securing standoffs and pins to one of the mounting plates. The functional elements are then assembled on the pins and the second plate is secured to the free ends of the standoffs to complete the assembly. Particularly important in this assembly process are the steps of forming holes in the mounting plate and inserting and securing the standoffs and pins in the corresponding holes. Punching or stamping machines are typically used to form the holes for the standoffs and pins. The mounting plate itself may be stamped from a sheet of stock in the same stamping operation used to form the holes. Once holes of suitable size are pierced at desired locations, standoffs and pins are mounted to the plate in separate operations. The standoffs are generally secured to the plate by peening or rolling an end of the standoffs protruding through the plate. The pins, which may be knurled or splined, at least in the region to be inserted in the plate, are typically pressed or otherwise force fitted into suitably dimensioned holes. Throughout these operations, the quality of each joint and the angular alignment of all standoffs and pins must be monitored to ensure that the final assembly will meet acceptable manufacturing tolerances.
While such conventional assembly techniques have been used for many years in the fabrication of a wide variety of mechanical and electro-mechanical devices, they are not without drawbacks. Specifically, a disadvantage of such techniques is the relatively large number of process steps required to align, insert and secure the standoffs and pins. Moreover, as the number of such process steps increases, so do the material handling and assembly times, as well as quality control costs. In addition, such techniques do not always provide secure and reliable mounting, ultimately resulting in reduced life and high maintenance costs for the finished product.
The present invention advantageously provides an improved method and apparatus for mounting standoffs and pins to a plate, wherein a plurality of standoffs and pins can be inserted and secured to the plate in a single operation. The method and apparatus also inherently provide control of the angular alignment of the standoffs and pins with respect to the plate.